Compressed air tool

ABSTRACT

A turning device ( 11 ) for compressed air tools ( 10 ). which is operated by a compressed fluid, is provided with a housing ( 16 ) and with a rotor ( 12 ), which is rotatably arranged in a front housing part ( 17 ) and into whose turbine element the fluid, which is under pressure, can flow, has a braking arrangement ( 14 ) and a switch ( 36 ) for the compressed fluid, which is in operative connection with the braking arrangement ( 14 ) and is arranged on a rear housing part ( 21 ) in line with a compressed fluid supply conduit ( 26 ). So that such a turning device ( 11 ) requires fewer components and can be stopped in a simpler and faster way by means of a fluid switch ( 36 ), a sliding switch ( 36 ) is provided, which encloses the rear housing part ( 21 ) in the area of the supply conduit ( 26 ) and is provided with axially oriented control pins ( 41 ), which are connected, fixed against relative displacement, with a brake disk ( 44 ) of the braking arrangement ( 14 ).

DESCRIPTION

[0001] The invention relates to a turning device operated by compressedair, for example for compressed air tools as described in the preambleto claim 1.

[0002] With such a turning device known from U.S. Pat. No. 5,186,603,the switch constitutes at least partially the rear housing part and canbe rotated in a screw thread in relation to the front housing part and ahousing cover which receives it. The supply with compressed fluid isopened or closed by means of this rotation. The braking arrangement isspring-loaded and is pressed on the rotor in the course of closing thecompressed fluid supply conduit when the switch is turned.

[0003] The construction of this known turning device is comparativelyelaborate and requires a multitude of components. Moreover, opening andclosing the compressed fluid supply conduit cannot be performed with onehand and is therefore impractical and furthermore time-consuming becauseof the multitude of required revolutions.

[0004] It is the object of the present invention to create a turningdevice of the type mentioned at the outset which requires fewercomponents and which can be brought to a stop in a simpler and fasterway by means of a fluid switch.

[0005] The characteristics recited in claim 1 are provided for attainingthis object in a turning device of the type mentioned.

[0006] By means of the steps of the invention it is achieved that theswitch is embodied as a simple sliding switch which cannot only beoperated with one hand, but also in a very rapid manner. The directopening and closing of the braking arrangement by means of the slidingswitch is possible because of the slide-proof connection of the brakedisk and the sliding switch without requiring further components.

[0007] A slide-proof guide for the control pins is achieved by means ofthe characteristics of claim 2. With the characteristics of claim 3,venting can take place simultaneously with the shutoff and braking ofthe rotor.

[0008] Advantageous embodiments in respect to opening and closing thecompressed fluid supply conduit with the aid of the sliding switch ensuefrom the characteristics of one or several of claims 4 to 6.

[0009] Further details of the invention can be taken from the followingdescription, in which the invention is described in greater detail andexplained by means of the exemplary embodiment represented in thedrawings.

[0010]FIG. 1 represents a compressed air tool provided with a turningdevice in accordance with a preferred exemplary embodiment of theinvention in the switched off and braked position in longitudinalsection and truncated form, and

[0011]FIG. 2 a truncated representation corresponding to FIG. 1, but inthe operating position.

[0012] The compressed air tool 10 represented in the drawings has aturning device 11, which h as a rotor 12, for example in the form of aturbine, which can be charged with compressed air and in this way causedto rotate. The supply of compressed air can be turned on or off by meansof a sliding switch 13, wherein a braking arrangement 14 acts on therotor 12 simultaneously with the shutoff of compressed air by means ofthe sliding switch 13.

[0013] The compressed air tool 10 has an elongated housing 16surrounding a drive shaft 18, which is connected, fixed against relativerotation, with the rotor 12 and is provided with a clamping chuck 19 onits end projecting out of the housing 16. The drive shaft 18 isrotatably seated in the housing 16 in the area close to the rotor 12, aswell as in the area remote from the rotor 12 and close to the clampingchuck 19.

[0014] The front housing part 17, which faces the rear housing part 21and can be connected with it, is embodied in a cup shape on one end 22.The cup-shaped end 22 is closed by a cover element 23 of the rearhousing part 21. A tube element 24 of the rear housing part 21 passesthrough the cover element 23, which tube element 24 has an axiallycentered, axial supply conduit 26 for the compressed air. Here, thecover element 23 and the tube element 24 are one piece. The supplyconduit 26 terminates in the turbine rotor 12. The supply conduit 26 isinterrupted in the tube element 24 outside of the cover element 23.Several radial bypass conduits 31, or 32, which extend from the outercircumference of the tube element 24 and are respectively arrangedevenly distributed over the circumference, terminate in the closed ends27 and 28 of the supply conduit 26 which are facing each other. Asleeve-shaped slide 36 is axially movable on the tube element 24provided with a smooth cylindrical exterior circumference 29 andprovided with a connecting end 33 for a compressed air connection. Thesleeve-shaped slide 36 is used as a switch for supplying and blockingcompressed air supplied via the supply conduit 26 and used for drivingthe turning device 11. The slide 36 has an interior annular groove 37which can connect the radial bypass conduits 31 and 32 of the two closedsupply conduit ends 27 and 28 with each other. In accordance with FIG.2, the annular groove 37 has a width corresponding to the radial bypassconduits 31 and 32, so that in the connected position of the slidingswitch 36 the outlet openings of the radial bypass conduits 31 and 32are covered by the annular groove 37 and are connected. An O-ring 33, ortwo O-rings 39 and 40, are arranged on both sides of the annular groove37 and prevent leaks to the outside in the connected state and, in thestate of the sliding switch 36 in which it interrupts the compressed airsupply, the center O-ring 40 of which is arranged at a place between thetwo radial bypass conduits 31 and 32 (FIG. 1). In this position thebypass conduits 31 are not connected with the bypass conduits 32, sothat the compressed air supply is interrupted.

[0015] The sleeve-shaped slide 36 has several, for example three,control pins 41, which are arranged evenly distributed over thecircumference and extend in the axial direction. The control pins 41 aremaintained with one end in blind bores 42 of the sleeve-shaped slide 36,pass through guide bores 43 in the cover element 23 in an axiallymovable manner and on their end located inside the cup-shaped end 22 ofthe front housing part 17 are connected, fixed against relativedisplacement, with a brake disk 44 of the braking arrangement 14. Thebrake disk 44, which is equipped with a ring-shaped brake lining 46, isaxially movable on the inner end of the tube element 24 facing the rotor12.

[0016] A connection, fixed against relative displacement, of the slide36 with the brake disk 44 is provided with the aid of the axial controlpins 41 so that, when the sliding switch 36 is in a position where itinterrupts the supply of compressed air (FIG. 1), the brake disk 44presses with its brake lining 46 against an annular front 47 of therotor 12. In accordance with FIG. 2, when the compressed air supply isopen, the brake disk 44 is at an axial distance from the rotor 12. Thecover element 23 is furthermore provided with axial vent openings 48 forventing during operation.

[0017] Even though the turning device 11 has been described inconnection with a compressed air tool 10, it is understood that theturning device 11 can also be employed with a tool operated by means ofa different compressed fluid.

1. A turning device (11) operated by compressed air, for example forcompressed air tools (10), having a housing (16) and a rotor (12), whichis rotatably arranged in a front housing part (17) and into whoseturbine element the fluid under pressure can flow, having a brakingarrangement (14) and a switch (36) for the compressed fluid, which is inoperative connection with the braking arrangement (14) and is arrangedon a rear housing part (21) in line with a compressed fluid supplyconduit (26), characterized in that a sliding switch (36) is provided,which encloses the rear housing part (21) in the area of the supplyconduit (26) and is provided with axially oriented control pins (41),which are connected, fixed against relative displacement, with a brakedisk (44) of the braking arrangement (14).
 2. The turning device inaccordance with claim 1, characterized in that the control pins (41) areguided in and through a cover (23) of the housing (16).
 3. The turningdevice in accordance with claim 2, characterized in that the housingcover (23) is supplied with vent openings (48).
 4. The turning device inaccordance with at least one of claims 1 to 3, characterized in that thesupply conduit (26) is interrupted in the rear housing part (21), andeach end (27, 28) of the supply conduit (26) is connected with radialbypass conduits (31, 32) arranged in the rear housing part (21), whoseoutlet openings can be covered by the sliding switch (36).
 5. Theturning device in accordance with claim 4, characterized in that thesliding switch (36) has an interior annular compressed fluid groove(37), whose width corresponds to the axial distance of the bypassconduits (31, 32) from both ends (27, 28) of the supply conduit (26). 6.The turning device in accordance with claim 5, characterized in thatseal rings (38, 39, 40) are provided in the sliding switch (36) at bothsides of the annular groove (37), the center seal ring (40) of whichseparates the two bypass conduits (31, 32).